Background
Clerkenwell Lifestyle (UK) Limited engaged HG Construction Limited under an amended JCT Design and Build Contract 2016, executed in December 2021, to construct a 153-room hotel (Section 2) and nine affordable apartments (Section 1) in Clerkenwell, London. Original contractual completion dates were 10 May 2023 for the residential section and 20 June 2023 for the hotel. During 2022, HG reported delays attributable to a Covid outbreak, underground obstructions, transport strikes, adverse weather, and material supply issues, and sought a 12-week extension of time. Following negotiations conducted through Avison Young (AY) as Employer’s Agent, the parties exchanged emails on 8 February 2023 in which AY set out proposed terms — including cost-sharing of party-wall fees and agreement in principle to a further extension once a scaffold addendum was agreed — and HG replied the same day confirming agreement. On 9 February 2023 AY issued a formal Notification of Extension of Time for 12 weeks, citing exceptionally adverse weather and strike action as Relevant Events, and fixing new completion dates of 15 August 2023 (Section 1) and 12 September 2023 (Section 2). A further extension was granted in September 2023, moving the dates to 24 August 2023 and 21 September 2023 respectively.
The works were completed significantly later: the hotel section achieved practical completion on 17 October 2024 and the residential section on 21 February 2025. Clerkenwell issued non-completion and liquidated-damages notices in mid-2024 and withheld £500,230 in liquidated damages by way of pay-less notices, then demanded a further £1,161,770. When HG disputed this — asserting entitlement to additional extensions for events including UKPN power-supply delays, a boiler plant-room redesign, and a Building Control certification dispute — Clerkenwell commenced adjudication in November 2025 before adjudicator Matthew Molloy, claiming approximately £1.127 million in further liquidated damages.
The adjudicator issued his decision on 5 January 2026. He rejected HG’s argument that time was at large, assessed all delay events using the original contractual completion dates as the baseline (consistent with the agreed baseline programme both delay experts had used throughout the adjudication), and fixed revised completion dates of 12 November 2023 for Section 1 and 21 October 2023 for Section 2. Only after the decision did HG raise, via a “slip rule” submission, the argument that the February 2023 email exchange constituted a binding settlement agreement that fixed immutable revised completion dates, and that the adjudicator should therefore have added his assessed extensions only to the September 2023 dates — which would have produced materially later dates and correspondingly lower liquidated damages exposure.
The Court’s Holding
Mrs Justice Jefford heard Clerkenwell’s Part 7 application for summary judgment to enforce the adjudicator’s decision alongside HG’s Part 8 claim seeking declarations that the decision was made in excess of jurisdiction and in breach of natural justice and was therefore unenforceable. The court found that the binding-agreement argument had not been advanced before the adjudicator during the substantive proceedings: HG’s own delay expert, Mr Anderson of HKA, conducted his Windows analysis from the original October 2021 baseline programme using the original contractual completion dates, and at the joint experts’ meeting on 17 December 2025 both experts presented shared agreement on those baseline dates. HG’s post-decision slip-rule submission sought not correction of a clerical error but a fundamental change to the adjudicator’s entire analytical framework — one that had never been placed before him for determination.
The court applied the principles in Hutton Construction Ltd v Wilson Properties (London) Ltd [2017] EWHC 517 (TCC) and the Court of Appeal’s guidance in A&V Building Solutions Ltd v J&B Hopkins Ltd [2023] EWCA Civ 1418 on the narrow circumstances in which a Part 8 challenge may properly be determined alongside Part 7 enforcement proceedings. Even on the assumption that the 8 February 2023 email exchange amounted to a binding agreement, it was not a dispute that had been referred to or decided by the adjudicator; it could not retrospectively confer jurisdiction on or strip jurisdiction from the adjudicator for matters he had decided consistently with the scope of the dispute as referred. Accordingly, the court granted summary judgment enforcing the adjudicator’s decision and declined to make the declarations sought by HG.
Key Takeaways
- A contractor cannot defeat adjudication enforcement by raising, for the first time in a post-decision “slip rule” submission, a binding-agreement argument that was never placed before the adjudicator and that its own expert’s evidence implicitly contradicted throughout the proceedings.
- Where both parties’ delay experts agree on a baseline programme and proceed on that basis throughout an adjudication, the adjudicator’s adoption of that same baseline does not constitute an excess of jurisdiction or breach of natural justice merely because the resulting dates differ from those a party later claims were contractually fixed.
- The slip rule corrects clerical errors; it cannot be used to require the adjudicator to adopt an entirely different methodological starting point — doing so would be a new decision, not a correction.
- Scope of a Part 8 declaration challenge is strictly confined: a court will only enturn an adjudicator’s decision on a question of law that arises on a narrow documentary basis and is genuinely determinative of enforceability, not on arguments that were never ventilated before the adjudicator.
Why It Matters
This decision reinforces the TCC’s robust approach to adjudication enforcement. It signals that parties who allow a full adjudication to proceed — with expert evidence, a joint baseline programme, and extensive pleadings — without raising a fundamental contractual objection cannot then seek to unravel the decision by recharacterising prior correspondence as a settlement agreement after an adverse outcome. The case is a practical warning to contractors: if an extension-of-time notification is said to reflect a binding compromise that constrains future dispute resolution, that position must be taken clearly and consistently from the outset, including in the instructions given to delay experts.
More broadly, the judgment illustrates the distinction the TCC draws between a true jurisdictional challenge (which may be raised at enforcement) and a disguised merits challenge dressed in jurisdictional language. HG’s contention that the adjudicator was not “tasked with deciding” the starting-point completion dates was undermined by its own procedural choices in the adjudication, and the court refused to allow the enforcement stage to become a re-run of the substantive dispute.